System of motor control.



I. 0. SMITH.

SYSTEM OF MOTOR CONTROL,

APPLICATION FILED MAYS, I9I3.

1,149,600. Patented Aug, 10, 1915.

a {I a 61/ WITNESSES 5W A TTORNE 1".

JOHN C. SMITH, OF LOUISVILLE, KENTUCKY.

SYSTEM OF MOTOR CONTROL.

Specification of Letters Patent.

Patented Aug. 10, 1915.

Application filed May 8, 1913. Serial No. 766,254.

To all whom it may concern Be it known that I, JonN G. SMITH, a citizen of the United States, residing in Louisville, in the county of Jefferson and State.

whereby the field may be excited before can rent is given to the armature, thereby obtaining a maximum torque at the instant of starting.

A further object is the maintaining of the excitation of the field after current is cut off fromthe armature, thereby obtaining a maximum dynamic braking ellect.

A still further object is the provision of means whereby the various steps may only occur in a predetermined sequence.

With the foregoing and other objects in view, my invention consists of the novel arrangement ofcircuits and apparatus to be hereinafter referred to, and illustrated in the accompanying drawings, which form a,

part of this specification, in which is set forth anembodiment of my invention, but it is to be understood that changes, variations and modifications may be resorted to that come within the scope of the claims appended hereunto.

In the drawing, in which similar reference numerals indicate like parts in the different views; the drawing is a diagrammatic plan, or wiring diagram, showing an embodiment of my invention wherein the various parts are at rest, showing in dotted lines the position assumed by parts when the car switch is ,moved partly over, to run the elevator up.

Referring to the drawings, -A indicates a main potential switch, B an accelerating switch, C, I) dynamic resistances switches, E a secondary or field switch, F- a speeding-up switch, G L reversing switch, H a wall switch, --I- a compound wound motor, J an automatic limit switch, K a manually operated car switch, --L' a slack cable switch,

M a brake magnet, -N a slow-down sw tch, OP upper and lower limit switches respectively. These devices are well known in the art, with the exception of E, and need no extended description. as anv desired construction may be utilized, though preferably I have illustrated those shown and described in my copenlding application #636,825, filed July 5, 1911. The car switch K is of the class in which a contactor is adapted to be brought into contact with a series of contacts, in the operating circuits, when shifted in either direction from a central position of rest, current being given thereto, from the wall switchH by lines 27- slack-cable switch L and line 8 to contact 413. The continuity of the circuit is established in the car switch K by pressing on the stem 415-, thus forcing the contactor 41-l into contact with the sector contact -413. Moving the switch K to the right (the up direction) will bring elevation -zt03 into contactwith the fin ger 406 giving current to the reversing switch G, by lines 9- to and through the solenoid 302 thence by line 10 to the auto-limit switch J, thence by lines 113- to the wall switch H, this will set the reversing switch and associated levers 312 and 316- in the position shown by dotted, lines. The shifting of lever 312 brings itint-o contact with point -314 closing a gap in the continuity of the main switch circuit, and the shifting of the lever -316 closes it on point -319 giving current to the solenoid E of the secondary or field switch, -E-,.the circuit being from the switch H by lines 2G and 12 to, and through, E thence by line 13- to contact 318 through lever 316 and line 1 l to switch H. The switch E is of the plunger type contactors E E* and E insulatedly attached to a plunger -E and are adapted to be brought into contact with fingers -E"E -E -E and E F by the attraction of the plunger within a solenoid E and is provided with a, holding coil -E which is adapted to hold theplunger up, in case the circuit. through the main coil should he accidentally opened before the circuit through the holding coil.

In the normal, or open position, the contactor E bridges the fingers E"E completing a circuit across the terminals of the opening the parallel path just referred to,"

shunt field as follows, from terminal f by line 5 to E and from E by lines 4 and 3 to terminal f"; as the plunger is drawn within the solenoid contactor E closes on fingers E E before E clears E E. 'gBridging contacts E E connects the shunt field to the line as follows, from wall switch H by lines 2 and 6 through resistance RS through contacts E E line 5 to terminal f through shunt field 60 to terminal f", thence by line 3 to H. It will be observed that a parallel path is offered the line current by way of contacts E E and conductor 4 to wall switch H over which a portion of the line current will pass. By this method of giving current to the shunt field undue sparking at switch terminals is avoided, as fully set forth in my co'pending application #725,052, filed Oct. 11, 1912. Further movement of the plunger E causes the contactor E .to clear contacts ID -E,

the contactor E closes on fingers E E completing the continuity of the operating circuit of the main switch A, one gap of which was previously closed by the action of the reversing switch shifting the lever 312. It will be observed that the field is excited while current has not yet been given to the armature, it is also to be observed that contacts EE being in the operating circuit of the main switch, the same can not be operated until the switch E has completed its-movement. This arrangement assures the excitation of the field previous to the giving of current to the armature. F urther movement of the car switch K will bring contact 402 into contact with 405. This will give current to main switch A, the 'circuit being by line 16 to and through the auto-limit switch J, thence by line 17 to, and through, upper limit switch 0, thence by line 18 to contact 314, through lever 312, by line 19 to contact E from E by line 20 to, and through, solenoid 101,-of switch A, thence by line 21 to, and through, the pilot switch lever 211, by lines 23, 25 and 2 to switch H, this closes the main switch. Current is given to one side of the main switch, from switch H by line 2 to point 106, and by lever 104 to points 108, 110 andvll3; and from points 109, 111 through lever 105 to contact 107 thence by line 2 to switch H. Closing of the main switch gives current to the brake magnet M, as follows, from point 113 by lines 24, 25 and 2 to switch H. Vith the closing of the main switch current is given to the holding coils 303, 301 and E, of the reversing and field switches, from point 108 by lines 57, 58 and 59 to switch H. With the closing of the main switch current is given to the shunt field as follows, from point 110 by line 49 to, and through, the contacts of the speeding-up switch, F, thence by line 50 to, and

G, through 308, by line 32 to motor terminal a, through armature 62 to terminal a, by line 31 to, and through 310309 to contactor 305 on reversing switch, thence by line 33 to point 111 on the main switch A. This starts the motor up at slow speed. A further movement of the car switch will bring contact 401into contact with ,112 giving current to the accelerating switch B, by line 34, to, and through, the auto-limit switch J, thence by line 35 to and through the operating coil 201, thence by line 36 to, and through, pilot switch lever 215, by line 37 to point 109 .on switch A; this starts the accelerating switch which is illustrated as of" the class in which a series of members are operated serz'atz'm, by a solenoid, to cut resistances in and out of the series field and armature circuit, the first and last members to operate being connected with and adapted to shift pilot switch levers. The movement? of the first member 203 shifts lever 211 breaking the circuit. of the main switch A at 213, this would allow the main switch to drop out, but that in closing the main switch point 214, through lever'211 by lines 23 and 25 to 2. The energization of C and D opens a dynamic resistance circuit across the armature terminals that may be traced as follows, from the motor terminal a" by lines 32 and 40 to point D and by 40' to point C thence by parallel lines 41 and'42 to and through resistances .54: and 55, thence by lines 43 and 31 to the terminal a; two resistances are provided in parallel that each switch may only have to break the circuit at half the full amperage. The dynamic breaking circuit is not opened until after the accelerating switch B commences to operate, this is an advantage in starting with a loadthat would drivethe armature, before it receives line current to overcome the torque caused by the load.

Members 20345, of the accelerating switch, contact successively with points 207-8-9 cutting resistance coils 2727- 27 out of the series field and armature circuit, .206 contacts with 210 cutting out the series field entirely, the armature circuit then beingfrom point 110, on switch A, by line 26-.27 to, and through, the accelerating switch to point 210,thence by lines 4430 to 306, on the reversing switch through 308-by line 32 to motor terminal 'a through armature 62 to terminals a, by

line 31 to the reversing switch thence by line 33 to point 111 on the main switch. As the last member of the accelerating switch rises .it shifts the pilot lever 215, breaking contact at 217 and making it 218. Breaking the contact at 217 inserts resistance 219 in the circuit of the solenoid 201; closing it at,

218 gives current to one side of the speedingup switch F by line 46; current being given to the other side by a further movement of the car switch K bringing elevation 403 into contact with 407, the circuit being by line 47 to contact N', on the slow-down switch N, through lever N by line 48 to F. The energization of F opens the shunt field circuit,- from the main switch, at F thus inserting resistance HS in thefshunt field and speeding up the motor, the circuit being as previously described from H by lines 2 and 6 to E. To bring the motor to rest the switch K is returned to'a central position,

the various switches then operate in. sequence andmanner the reverse to that Just set forth. The switch 'F cutting the resistance RS out of the shunt field circuit, the accelerating switch as'it falls out cutting in the series field and resistances 27-, 27 and 27 into the armature circuit, as the last member falls out it opens the op erating circuit of the switches (3-D and these close the-dynamic circuit across the armature terminals, the'resistances 54-55 being in parallel and so proportioned that each will pass but one half the currentbut very little sparking occurs at the switch terminals. The main switch in falling out opens the armature circuit, the shunt field being held on the line by the switch E. The shunt field .remaining excited allows full advantage to be had of the braking effect ob tained by the surge of induced current in the armature circuit. The falling out of the main switch opened the circuit of theholding coils 303304 13 permitting the reversing and field switches to fall out. As the reversing switch falls out the circuit of switch E is opened at 319 allowing the same to fall out. The switch E is the last to fall out, and in so doing, by closing contact E 1 short circuits the field on itself before confacts E open and cut the line off. As the armature and shunt field circuits are each.

closed on themselves when the main line current thereto is cut off, it is evident that the induced current will surge around the closed circuits and there will be a minimum of sparking at switch contacts. If the in the field will not switch K is thrown over, in the reverse di- 2 rection, quicklythe reversing switch may be set and current given to the main switch, and consequently to the series field and armature, before the switch E falls out, this will result in a saving of current as the lag have to be overcome. Having thus described my invention so that any one skilled in the art may make and use the same, I claim Y 1. In a system of motor control, a motor, 1

a reversing switch, a main switch, operating circuits therefor, a'manual switch having contacts in said circuits and operative to close them in the sequence named, a field switch, means controlled respectively by said reversing and field switches to complete the continuity of the main switch operating circuit.

2. In a system of motor control, a motor, a main potential switch, a field switch, a reversing switch, operating circuits therefor, a manually operated switch adapted to controlled by the main switch for closing the circuit of said holding coils.

4. In a system of motor control, a motor, a main potential switch, a field switch, a reversing switch, operating circuits therefor, holding coils associated with the last two of 'saidswitches, said coils connected in series, a manually operated switch adapted to close the circuits of said reversing and main switches, means controlled by the reversing switch for closing the circuit of said field switch, and means controlled by the main switch for closing the circuit of said holding coils.

5. In a' system of motor control, a motor,

- a main potential switch, a field switch, a reversing switch, holdingcoilsfor the last-two named switches, said field switch adapted to be operated by closing of said reversing switch and said holding coils adapted to be energized by the closing of the main switch.

6. In a system of motor control, a motor, a main potential switch, a field switch, a reversing switch, holding coils for the last two named switches connected in series and adapted to be energized by the closing of the main switch, an operating circuit for said field switch adapted to be closed by a switch controlled by the reversing switch.

T. In a system of a reversing switch, a main switch,.an accelerating switch, operating circuits therefor, a manual switch having contacts in said circuits and operative to close them in the sequence named, a field switch adapted to be controlled by the reversing switch, means controlled respectively by the reversing and field switches for completing the continuity of the main switch operative circuit whereby the main switch may only be operated when said reversing and field switches have been properly set.

S. In a system of motor control, a motor, a reversing switch, a main switch, an accelcrating switch, a field switch, operating circuits therefor, a manual switch-having contacts in and operative to close the circuits of the first three named switches, a switch in the circuit of said field switch adapted to be closed on the operation of the reversing switch, means reversing switches'tor completing the continuity ot' the main switch operative circuit, holding coils associated with said field and reversing switches, said coils connected in series and adapted to be energized on the closing of the main switch whereby said field and reversing switches may not be opened while the main switch is closed.

t). In a system of motor control, a motor, a reversing switch, a main switch, an accelerating switch, a field switch, operating circuits therefor, a manual switch having contacts in and operative to close the circuits of the first three named switches, a switch in the circuit of the field switch adapted to be closed by the operation of the reversing switch, holding coils for the field and reversing switches connected in series and adapted to be energized on the closing of the main switch, means controlled respectively by the reversing and field switches for completing the continuity of the main switch circuit, an initially closed switch interposed in the main switch circuit and connected with a moving part of and adapted to be opened by the closing of the accelerating switch to br ark the continuity of the main switch circuit and prevent the operation of the main switch while the accelerating switch is closed 10. In a system of motor control, amotor, a reversing switch, a main switch, an accelerating switch and a speeding-up switch, operating circuits therefor, a manual switch having contacts in and operative to close said circuits, a field switch, an operating circuittheretor adapted to be closed by the reversing switch, holding coils associated with the field and reversing switches connected in series and adapted to be, energized by the closing of the main switch, means controlled respectively by the field and reversing switches for completing the conmotor control, a motor, tinuity of the controlled by said field andmain switch circuit, an initially open switch in the circuit of said speeding-up switch connected with a moving part of and adapted to be closed by the closing of the accelerating switch to establish the continuity of said speeding-up circuit.

11. In a system of motor control, a motor, a reversing switch, a main switch, and a. field switch, a pair of solenoids for operating the reversing switch, a solenoid for operating the field switch, a holding coil for each of said solenoids, said coils connected in series and adapted to be energized by the closing of the main switch, operating circuits for said reversing and main switches, a manual switch having contacts in and 0perative to close said operating circuits, a circuit for said field switch adapted to be closed by a switch controlled by the reversing switch.

12. In a system of motor control, a motor, a reversing switch, a main switch, and an accelerating switch operating circuits therefor, a manual switch having contacts in and operative to close said circuits in the sequence named, a field switch, an operating circuit therefor adapted to be closed by the reversing switch, holding coils for said a'ccelerating and field switches, an operating circuit for said coils adapted to be closed by the main switch, an initially closed switch in the main switch circuitadapted to be opened by the accelerating switch to break the continuity ot' the main switch circuit, a. speeding-up switch, an operating circuit therefor adapted to be controlled by the accelerating switch.

13. In a system of motor control, a motor, an initially closed circuit across the arm!!- ture terminals thereof, a plurality of resistances in parallel in said circuit, a plurality of switches having a common operating circuit adapted to control the current to said resistances, a reversing switch, a main switch and an accelerating switch, operating circuits therefor, a manual switch having contacts in and operative to close said circuits, an initially open switch in the operating circuit of the said plurality of switches, adapted to be closed by the action of the accelerating switch.

14:- In a system of motor control, a motor, an accelerating switch, a main switch, a manual switch having contacts in and 0perative to close circuits for said switches, a field switch and an operative circuit therefor, an initially open switch in said circuit adapted to be closed by the reversing switch, a plurality of initially open switches in the main switch circuit, the contactor of one of said switches connected to and adapted to be shifted by the reversing switch, the contactor ot' the other connected to the field switch.

15. In a system of motor control, a motor, an initially closed circuit across the armature terminals thereof, a plurality of resistances in parallel in said circuit, a reversing switch, a. main switch and an accelerating switch comprising a plurality of members operating serial/int, operating circuits for said switches, a manual switch having contacts in and operative to close said operating circuits in the sequence named, a field switch, a plurality of initially open switches in the main switch circuit, the contactor of one of which is connected to the reversing switch and the contactor of the other connected to the field switch, electromagnetic switches, one for each of the aforesaid resistances, controlled by.the first member of the accelerating switch and adapted to open the aforesaid closed circuit.

16. In a system of motor control, a motor, an initially closed circuit across the terminals of the shunt field thereof, a field switch having a plurality of contacts in said circuit and a plurality of contactors adapted to close on said contacts and adapted to admit line current to the shunt field before opening said closed circuit.

17. In a system of motor control. a motor, afield switch adapted initially to maintain a closed circuit across the terminals of the shunt field of said motor and when energized to admit line current to the shunt field before opening said closed circuit.

18. In a system of motor control, a motor, an initially closed circuit across the armature terminals thereof, and an initially closed circuit across the shunt field terminals thereof.

15). In a system of motor control, a motor, an initially closed circuit across the armature terminals thereof, a plurality of resistances in parallel in said circuit, a reversing switch, a main switch and an accelerating switch comprising a plurality of members operating scrimim, operating circuits for said switches, a manual switch having contacts in and operative to close said operating circuits in the sequence named, a field switch and an operating circuit therefor adapted to be closed by the reversing switch, a plurality of initially open switches interposed in the main switch circuit, the contactor of one of which is connected to a moving part of the reversing switch and the contactor of the other to the field switch, an initially closed switch in the main switch circuit, the contactor of which is connected to thefirst member of the accelerating switch, and a plurality of electromagnetic switches controlling the flow of current through the aforesaid plurality of resistances, said electromagnetic switches controlled by thefirst member of the accelerating switch.

20. In a system of motor control, the combination with an electric motor, of a main switch, a reversing switch and an accelerating switch, a braking circuit across the armature terminals of the motor, an initially closed circuit including the shunt field, means controlled by the setting of the reversing switch to admit current to the shunt field previous to opening said initially closed circuit, and means operable by the action of the accelerating switch to control said braking circuit.

21. In a system of motor control, the combination with an electric motor, of a main switch, a reversing switch, an accelerating switch and a field switch, a braking circuit across the armature terminals of the motor, an initially closed circuit across the shunt field terminals, means operable by setting of the reversing switch to energize said field switch whereby current is admitted to the shunt field through a resistance before said initially closed circuit is opened, and means operable by the action of the accelerating, switch to control said braking circuit.

In a system of motor control, the combination with an electric motor, of a. reversing switch, a field switch, a main switch and an accelerating switch, a braking circuit across the armature terminals including a plurality of parallel resistances, an initially closed circuit including the shunt field, means controlled by the setting of the reversing switch to energize said field switch whereby current is admitted to the shunt field before the initially closed circuit is opened, means operable by the accelerating switch to control said braking circuit.

23. In a system of motor control, the combination with an electric motor, of a reversing switch, a field switch, a main switch and an accelerating switch, a braking circuit across the armature terminals including a plurality of parallel resistances, an initially closed circuit including the shunt field, means controlled by the setting of the reversing switch for energizing said field switch whereby current is given. to the shunt field through a resistance before the aforesaid closed circuit is opened, said resistance adapted to be short circuited by the closing of the main switch and means operable by the accelerating switch to control said braking circuit.

24. The combination with a motor, of a reversing switch, a main switch, a field switch, operating circuits therefor, a circuit in parallel with the shunt field of the motor, means controlled by the reversing switch for energizing said field switch whereby current is given to'said shunt field and parallel circuit, and said parallel circuit is subsequently opened.

25. The combination with a motor, of a reversing switch, a main switch, a field switch, operating circuits therefor, acircuit in parallel with the shunt field of the motor, means controlled by the reversing switch for energizing said field switch, a resistance, said field switch adapted to give current to the shunt field and the parallel circuit and subsequently open the parallel circuit.

26. A motor, a main switch, a subswitch, a resistance, a circuit in parallel with the shunt field of the motor and normally closed by said subswitch, said subswitch adapted to give current through the resistance to the shunt field and said circuit and later to open said circuit, said main switch adapted to give current a direct to the shunt field thereby short circuiting said resistance.

27. A motor, a main switch, a circuit in parallel with the shunt field of the motor, said circuit normally closed by the subswitch, said subswitch adapted to give current through the resistance to the shunt field and said parallel circuit, an operating circuit for the main switch normally open at the subswitch, said subswitch adapted to open said parallel circuit and complete said operating circuit, said main switch adapted after the operation of the subswitch to give current to the motor direct thereby cutting out said resistance.

28. A motor, a main switch controlling current to said motor, a reversing switch controlling the direction of current through said motor, a circuit in parallel with the shunt field of the motor, a resistance, a subswitch adapted togive current through said resistance to the shunt field and said parallel circuit, said subswitch controlled by the reversing switch and controlling the main switch, said main switch adapted to give current direct to the shunt field short circuiting said resistance.

' JOHN G. SMITH.

Witnesses:

W'. B. MUNNELL, F. H. KAPPA. 

